Latias ex Special Illustration Rare

It’s never entirely clear why some cards do so spectacularly well, when equivalent cards fare far worse. Case in point: this lovely Latias ex, which doesn’t seem to be doing anything spectacularly more exciting than the equally lovely Latios down at $42. Sure, this one’s an ex, but the Latios is stacked too, and won’t cost you two prize cards when it’s knocked out.
However, that Skyliner ability is clearly a big deal, removing all retreat costs while it’s on your bench, meaning you can switch cards in and out as often as you want. I’m really interested to see what sort of decks will be built around this.
Still, I’d be really interested to know why it’s this card that’s changing hands for a mindblowing $205